Physicists in the UK have discovered that thin films of silver - a normally opaque material - can be made highly transparent by sandwiching them bewteen zinc-selenide-coated glass blocks.

Ian Hooper and colleagues at the University of Exeter say that the light passes through the silver in a similar way to how particles can tunnel through barrriers. The work could help to improve the efficiency of organic light-emitting diodes and enable a new generation of semiconductor devices. Phys. Rev. Lett. 97 053902).